Currently the headquarters of the municipal company Águas do Porto, hence its second name Parque das Águas (Water Park), the Nova Sintra Park is one of the largest green spaces in Porto, boasting great botanical diversity, dense trees, as well as a peaceful atmosphere--a nice place to relax and take a break by one of its many fountains.

Venture 27 kilometres north of Arrecife to discover some of the world's most awe-inspiring caves. The Jameos del Agua subterranean complex, formed 3,000 years ago by a volcanic eruption, boasts an array of volcanic formations, including lakes, caves, courtyards, and even a subterranean auditorium that regularly hosts concerts. Adjacent to Jameos del Agua, you'll find the remarkable Cueva de los Verdes, a lava tube situated within the protected area of Monumento Natural del Malpaís de La Corona. This tourist attraction features 7-kilometre-long tunnels and a mesmerising subterranean lake in its largest cave.

The United States naval base at Pearl Harbor was surprised by a Japanese military strike on the morning of December 7, 1941: all eight U.S. Navy battleships were damaged, more than 2,000 Americans lost their lives, and this very attack led to the American involvement in World War II. Today, a memorial reminds of those who died in the assault, while two museums and outdoor exhibits present the historical happenings and their backgrounds. The visitor centre in general also features exhibits and interpretive programs for other Pacific National Parks: Kalaupapa National Historical Park on the island of Molokai, American Memorial Park in Saipan, and War in the Pacific National Historical Park in Guam.

Near the Stock Palace and the Douro River is another UNESCO World Heritage site that is well worth visit while in Porto, the Monument Church of St Francis, or Igreja Monumento de São Francisco. This church built around the 14th century has one of Europe's most sumptuous and extravagant interiors. Here, all that glitter is, in fact, gold! Its interior is covered in gilded woodwork, and rumour has it that it was used around 400 to 600 kg of gold to decorate it. Hence why the St Francis Church is also known as "The Golden Church". Another highlight of this church is its impressive Tree of Jesse, a wooden sculpture carved by Filipe da Silva and António Gomes in 1718 depicting the ancestors of Jesus Christ, shown in a branching tree — considered to be one of the best in the world of its kind. Under the church, you will find the catacombs, where the Franciscan monks along with the members of Porto's noble families are buried.