The ancient Flavian Amphitheater was built by the Flavian emperors in 70 C.E. as a gift to the Roman people. As the largest Roman theater ever built, it was designed to house over 50,000 people, and had played host to gladiator games, plays and even public executions. Purchase skip-the-line tickets online to avoid long lines at the door, or join guided tours which allow for special access to restricted areas. While here, you might want to visit the adjacent Palatine Hill and Roman Forum as well. – Tripadvisor

Basilica de la Sagrada Familia is a church devoted to the Holy Family. One of Antoni Gaudi’s most famous works, the church is perhaps best known for still being under construction since 1882—with works funded purely by donations. Take a lift to the top of the towers for a panoramic view of the city and marvel at the ornate architecture. The nativity facade and crypt have also been awarded UNESCO World Heritage Status. Skip the line with a pre-booked tour with tower access, or combine your visit with another of Gaudi's work, Parc Guell. – Tripadvisor

Dedicated to the seven planetary divinities and featuring an interior of gorgeous marble, the Pantheon is one of the most impressive monuments of Augustan Rome.

This ancient citadel, built in the fifth century B.C., towers over the city and is home to some of the most impressive ancient ruins, buildings, and artifacts. The most famous temple, the Parthenon, was dedicated to the goddess Athena and is considered the peak of Greek art. You can avoid long lines by joining a walking tour of the site. Make sure to wear comfortable shoes and bring sunscreen, as the walk up the hill can be steep and exposed to the sun. For the best experience, visit early in the morning or late in the afternoon to avoid the heat and for fewer crowds. – Tripadvisor

Welcome to Barcelona's magical house. A Gaudí masterpiece. A unique immersive experience. International Exhibition of the Year 2022. Children free up to 12 years old.

Certainly the most famous and photographed fountain in Rome, legend has it that whoever throws a coin into the pond will return to Rome.

Stroll through the historic center of medieval Barcelona and visit some of the city's most important political buildings and gothic architecture.

The quirky colorful mosaics and undulating curves of Park Güell are a signature of the legendary Catalan architect Antoni Gaudi, who designed many of the features in this park. Officially opened in 1926 and initially planned as a district for the rich, it is now one of the city's most popular attractions and a great representation of Catalan modernism. The entrance with two fairytale-like houses and the iconic salamander fountain are the most busy. Tickets are required to enter the park.

Discover a hidden side of Rome in Trastevere, a non-touristy bohemian neighborhood located across the Tiber River. Get lost along the winding alleys, join a food walking tour, enjoy a panoramic view from Piazzale Garibaldi, or experience the district with a photography tour. The streets are lined with shops, trattorias, and bars; when night falls, Trastevere comes alive with al fresco dining, twinkly fairy lights, and live music. Visit on market days to check out the weekly Porta Portese market, Rome’s largest flea market. – Tripadvisor

Officially known as the Mercat de San Josep as it was built on a former monastery, La Boqueria is a popular food market along Barcelona's touristy La Rambla stretch. Dating back to the 13th century, this colorful market is the largest in the city, home to more than 300 stalls renowned for selling some of the freshest produce—including meats, vegetables, cold cuts, sweets, and seafood. Join a food and drink tasting tour with a local to better enjoy the delicious delicacies on display and learn more about the market's history. The market can be easily reached by the metro. – Tripadvisor