Portugal gets high marks from some of the go-to experts on retirement abroad – Live and Invest Overseas rated the country's Algarve region as the No.1 retirement destination in the world two years in a row, and International Living gave Portugal an 84.8 out of 100 in its 2015 index of best places to retire. Would-be retirees are attracted by the climate, the scenery, the culture and history as well as the country's favorable tax plans, excellent infrastructure and one of its biggest draws – its low cost of living.

Once you've decided that Portugal might be the place for you to retire, you'll want explore which part of the country would be best. Do you want to be in a place with lots of expats like the Algarve region, which has a climate much like southern California? Or in the north in a university town? Or perhaps in the energetic capital city of Lisbon or in one of the beach towns on the Silver Coast, an easy train ride from the capital?

Here are four cities to consider.

[Prices are converted from euros, at the late fall 2015 rate of one euro to US$1.06.]

The Algarve area in the very south of the country has been a favorite with the British for decades – both as a vacation and a retirement destination. Greg Boegner, founder of the blog Portugal Confidential, says that the Algarve is the best place for anyone looking for a relaxed style of life and some of the best golf courses in the world. Each town along the coast has a community of expats who organize events and dinners. Culture is limited in this area, giving way to beach life.

The author of the irreverent blog Piglet in Portugal has a few words of caution about making the Algarve your permanent home, however: Taking a vacation for a few weeks a year is not the same as living in a tourist hotspot. For most people it is a fun experience but for those who don't embrace the holiday spirit, it can be hell on earth.

The town of Lagos (pronounced lah-goosh) is part of the tourist-y scene but has much to recommend it: It lies along the bank of the Rio Bensafrim and offers the undisputed charm of a 16th-century walled town with cobbled streets, whitewashed houses and picturesque plazas. The town's good and inexpensive restaurants, a range of fabulous nearby beaches, its spring-through-fall calendar of open-air jazz and classical concerts and a throbbing night life all beckon.

Lagos is also a piece of Portugal where some great real estate bargains can be had: Just recently Kathleen Peddicord, the publisher of Live and Invest Overseas, bought a two bedroom apartment for just over $100,000.

(If you're considering buying a home abroad, see How To Finance Foreign Real Estate and Do You Get U.S. Tax Deductions On Real Estate Abroad?)

Lisbon is the capital city, the main driver of the country's economy. As you would expect, it's a very cosmopolitan city. It has dozens of museums to see (especially the wonderful Gulbenkian), a world class orchestra, even an English language theater group and of course, tons of wonderful bars and restaurants, according to Dennis Shay, a retiree who lives in Portugal.

Lonely Planet describes Lisbon as having all the delights you'd expect of Portugal's star attraction, yet with half the fuss of other European capitals. Gothic cathedrals, majestic monasteries and quaint museums are all part of the colourful cityscape, but the real delights of discovery lie in wandering the narrow lanes of Lisbon's lovely backstreets.

John Malkovich (yes, that John Malkovich) thinks Lisbon is perfect for retirement according to an interview he did with a website called Portugal is Paradise. What makes it so? Malkovich cited the people, who are friendly, smiling and terrific, plus the location, the geography, the architecture, the food and, of course, fado music. (Fado is a uniquely Portuguese style of song popular in cafés and bars – the songs are melancholic, all about destiny and the struggles and sadness of life and love.)

In Lisbon, public transportation by bus and metro is plentiful and inexpensive – you won't need to own a car in Lisbon and that will keep your monthly costs down significantly (gasoline and toll roads are a big expense in Portugal). A small apartment in Lisbon can be rented for about $600; a meal in a mid-range restaurant is about $40 for two.

For retirees with wanderlust, Lisbon is the perfect starting point for jaunts to other cities in Portugal, in both Europe and Africa. It's a two-and-a-half-hour flight from Lisbon to Paris, just over one hour to Casablanca. And you'll have your pick of bargain fares from the discounted European airlines that fly out of Lisbon airport.

A 25-minute train ride from Lisbon, this coastal town (pronounces Cahsh-Kaish) is where the Shays chose to retire because, they say, besides good weather and a reasonable cost of living, the beaches are spectacular, the town is charming and the local government is very active in providing entertainment and learning opportunities. It seems like there is some sort of festival just about every week.

A favorite with expats, Cascais is a welcoming place: It was very easy to get connected with expats, and we soon developed quite a social network, according to Dennis Shay. There aren't many American expats in Cascais, which was one of the attractions for the Shays, who wanted to get to know people from other cultures which we certainly did.

One expat, writing on Expat Exchange, calls Cascais IDEAL (the caps are hers). Why? We have generally reliably nice weather, pristine beaches, restaurants everywhere on the narrow streets and squares as well as along the pedestrian esplanade by the ocean.

One retiree, writing for the Wall Street Journal, likes this pretty and cosmopolitan town with a climate like southern California. For the active retiree (myself included …) there is plenty to do: golf, sailing, diving, biking – you name it. For the more sedentary, there is gardening, an avid bridge-playing set of folks and other interest groups. Living here, all of the great cities of Europe are at your doorstep. You can drive to Madrid, Seville or Barcelona in Spain. The south of France is a day's drive away.

Many people like the idea of retiring to a university town, and Coimbra, in north central Portugal, has been exactly that since the 1500s when the university moved from Lisbon to its present location on the Mondego River. Two hours from Lisbon by train, Coimbra is Portugal's version of Oxford, according to International Living. Students clad in black cloaks are a regular sight on the steep cobbled lanes running up to the grand university that dominates the town. Coimbra is one of the oldest universities in Europe, originally founded in 1290. In the 12th century, the town was the capital of Portugal. Now it has a population of 106,500, almost a quarter of them university students. It is a town with a mix of the old and the new – medieval churches and chill-out bars.

The climate in Coimbra is mild – in the 40s in winter and rarely higher than the 80s in the summer – more often in the 70s.

The bar scene around the old cathedral is lively, and Café Santa Cruz, with its vaulted ceilings and stained glass windows, has been a popular gathering place for poets, writers and artists since 1929.

Many of the outdoor events in town are linked to the university – for instance, the lively street parties on New Year's Day. In June, the town hosts an international Jazz Festival and every week during the summer months you can find a fado concert somewhere in town.

According to International Living, buying a retirement home in Coimbra is less expensive than in Lisbon or the towns in the Algarve: Most foreign buyers prefer to pick up old homes with some land within a 30-minute drive of the city of Coimbra. And there are plenty of those on the market. But head into the city, and you'll find decent apartments for sale from as little $70,000 or so. Perfect lock and leave bases if you're exploring Europe. Plus, with thousands of students in Coimbra, there is the opportunity to rent your place out.

Finding the ideal retirement destination in Portugal requires two things – researching all aspects of life in the places you're considering and doing some honest-to-goodness soul-searching about what kind of retirement you want. Golf and living a beach-centric life? A big-city vibe? A cultural and learning center to call home? Keep in mind that places that are perfectly dreamy for a two-week vacation may not be at all suited to a year-round life. Use your social network to find others who have retired to Portugal and ask them every question you can think of. Then, when you've decided on a destination, spend at least a month in your chosen city or town and live like a local before putting down more permanent roots.

To lay the groundwork for retiring abroad, you may be want to read Plan Your Retirement Abroad and What Does Retirement Abroad Cost?

See also: Retire in Brazil with $200,000 of Savings? and The Top 3 Regions To Retire In Spain.