Most of Bangkok's sights are concentrated on the island of Rattanakosin, often referred to the "Old City". Out of Bangkok's hundreds of temples, the Grand Palace, Wat Pho and Wat Arun usually make up the top 3. The Grand Palace has an immense size, so expect to spend at least a full morning or afternoon there. Within the palace grounds is Wat Phra Kaew, the most sacred Buddhist temple of Thailand. Unlike other temples, it is not one building, nor are there are living spaces for monks. Instead, it is a collection of highly decorated holy buildings and monuments.

Nearby is Wat Pho, home to the world's largest reclining Buddha image and a famed massage school. Take the ferry across the Chao Phraya river to Thonburi for the outstanding Wat Arun. The main structure is about 60 to 88 meters high and it is surrounded by four smaller prangs. It is one of Thailand's most picturesque temples, and it is engraved on the inner part of all ten baht coins. If you climb it, and look closely, you will see that it is beautifully decorated with colorful broken Chinese porcelain pieces. Heading back to Rattanakosin, there are many other major temples you could visit, including the Golden Mount, Wat Suthat and Wat Ratchanadda.

Don't throw away the entry ticket of the Grand Palace, as it gives free entry to the Dusit Palace in Dusit. It is situated in a leafy, European-style area built by King Rama V to escape the heat of the Grand Palace. Its main structure is the Vimanmek Mansion, the largest golden teakwood house in the world, but you could spend your whole day in the museums here if you want. There are many other museums in Bangkok showing traditional Thai-style residences. Most visitors take a tour through Jim Thompson's House, the CIA-operative's mansion assembled by combining six traditional Thai-style houses, conveniently located near Siam Square. Ban Kamthieng in Sukhumvit, M.R. Kukrit's Heritage Home in Silom and the Suan Pakkad Palace in Phahonyothin could also make for a nice experience. Rattanakosin has many museums about history and culture, including the National Museum about Thai history and archaeological remains, the Museum of Siam and the King Prajadhipok Museum. Bangkok has a small, but vocal art community, and you might want to visit the National Gallery, The Queen's Gallery, or one of its numerous smaller galleries. Siam Square has the Bangkok Art and Culture Centre which has temporary art exhibitions throughout year.

Lumphini Park in Silom is the largest park in central Bangkok, and a good way to escape the fumes. Backpackers around Khao San Road can head for Santichaiprakarn Park, a small but fun park along the Chao Phraya river with a breezy atmosphere, usually with locals juggling or practicing tricks. It is built around the Phra Sumen Fort with a nice view on the modern Rama VII cable-stayed bridge. Zoos and animal farms are some of the most popular tourist attractions in Bangkok, but before visiting, please be aware that animal welfare in Thailand is not strictly regulated. Poor living conditions of the animals and inadequate veterinary care are examples of the sad mistreatment of the animal population. You can't go wrong at the Queen Saovabha Snake Farm, as the staff takes good care of their snakes and they have a job of informing the public about their risks. Another nice family attraction is Siam Ocean World in Siam Square. It has a steep price tag, but you get the largest aquarium in Southeast Asia for it.