The two most visited cities in Spain also happen to be the largest. Indeed, coastal Barcelona and inland Madrid are both booming metropolises. But they also contain treasure-troves of historic buildings, ancient churches, pretty plazas and interesting neighborhoods. Here is a peek at some of the top attractions in each city:

Beautiful Barcelona

On the northeast coast of the Iberian Peninsula, Barcelona enjoys a Mediterranean climate; you can generally expect warm, dry summers and mild, humid winters. On a pretty, clear day, it's ideal weather for strolling through Barcelona's Gothic Quarter, the oldest district of the city. Here, find the Cathedral of the Holy Cross and Saint Eulalia, also known simply as the Barcelona Cathedral, built between the 13th and 15th centuries. Be sure to look up and admire the ornate steeples and roof of this cathedral, where you'll see several gargoyles and animals carved in stone.

Antoni Gaudi is Barcelona's most famous Art Nouveau architect, and you can see his fine work in the Sagrada Familia, a huge Roman Catholic church that has been under construction since 1882. It's still not complete. However, hundreds, if not thousands, of tourists visit daily, and it has been named a UNESCO World Heritage Site. Pope Benedict XVI deemed it a minor basilica in 2010; the church is scheduled for completion in 2026, the 100th anniversary of Gaudi's death.

Gaudi also designed urban parks; his Park Guell is known for its main terrace surrounded by a long bench in the shape of a sea serpent. Admire his intricate, colorful mosaic work while people watching in this busy park. You might also mingle with the locals at one of Barcelona's many bustling food markets, such as La Boqueria on La Rambla pedestrian mall, where vegetables, produce, meat and fish are for sale. Want to hit the beach while vacationing in Barcelona? No problem! There are seven distinct sandy beaches over nearly three miles of coastline.

Marvelous Madrid

The capital of Spain is strikingly modern, but is home to a wealth of historic and cultural attractions. One very famous landmark is the Royal Palace, the King of Spain's official residence in Madrid, though it is used only for state ceremonies (the king and his family live in a more modest palace outside of the city). Visitors are welcome to enter the Royal Palace to see such sights as the Throne Room, the Hall of Columns and the imperial ballroom.
Rectangular Plaza Mayor is the city's central plaza, surrounded by red-brick residential buildings. Nearby Puerto del Sol ("Gate of the Sun") is a popular gathering place among locals and tourists; note the interesting sights here, including "kilometer zero," a plaque marking the symbolic center of Spain near the old post office. Many visitors snap photos in front of the Bear and the Madrono Tree statue here.

Art lovers will want to visit the Prado Museum. Many Spanish works hang here, but it's also known for the wide range of European art spanning the 14th to 19th centuries. The other important gallery in Madrid is the Queen Sofia Museum, which houses more modern pieces, including paintings by Picasso and Dali.

Shoppers should head to El Rastro, with its market stalls stocking everything from clothes and accessories to home-decor items. It gets crowded here, so be prepared to go with the flow! You'll also find crowds at Madrid's football (soccer) stadium; the Real Madrid football club is the current reigning World Cup champion. If you'd really like to do as the locals do in Madrid, take a nap in the afternoon, then head out on the town for its very vibrant nightlife. You'll find dozens of options for tapas bars, cocktail bars, clubs, jazz lounges, live music venues and flamenco theatres. Before heading back to your hotel, stop for churros con chocolate – a thick cup of hot chocolate and a sweet fried treat!