Originally a medieval castle called Kastello, it was destoyed in 1856 and resurrected in 1939. Now, it's the crown jewel of the Old Town. Inside, ancient mosaics bedeck the floors, and you'll find a unique collection of 16th and 17th-century Western furniture. On a hot day, the castle's massive walls provide a much-needed reprieve from the heat.

Cișmigiu Gardens, the oldest park in Bucharest designed by Carl Meyer in the 1850s, features a stunning rose garden in the north and a classic French garden on the west. Stroll along its tranquil paths or rent a boat to explore the largest lake, complete with its own island. This charming park offers a peaceful retreat, steeped in the city's history and elegance.

The historic Saigon Central Post Office, which has long been one of the city's symbols, continues to offer postal services such as mailing and money exchange to-date. One interesting fact about the Post Office is that it was designed and constructed by the renowned French architect Alexandre Gustave Eiffel, who is best known for the eponymous Eiffel Tower. Eiffel derived artistic inspiration from Western neoclassical architecture and Asian decor styles before harmoniously fusing them during the construction of the Central Post Office.

Once used for shipping in the late 1800s and early 1900s, the piers are now used for their views. The Avila Beach Pier is the first of the three piers and was first constructed in 1908 by the county of San Luis Obispo. Over two thousand local residents gathered there on April 30th, 1908 when President Teddy Roosevelt's 'Great White Fleet' anchored offshore. The Harford Pier was developed in 1873 and is now used for fishing, restaurants and commercial fishing. The last pier, the California Polytechnic State University Pier, is an educational and marine research facility.