On our first day in Bangkok, we booked a tour guide, Nina with YTG - Your Thai Guide for a full day of exploring. We told her what we wanted to see and do and she made it happen! One of the top items on our list was The Grand Palace. We took a taxi here and spent a few hours walking around, visiting the museum, and learning about the history and religion.
The Grand Palace in Bangkok was built in 1792, and is stunning. The grounds were beautiful, the colors were wonderful, and the architecture was lovely. It is certainly a must-do if you are in Bangkok. It is divided into four main courts, the Outer Court, Middle Court, Inner Court, and the the Temple of the Emerald Buddah (aka Wat Phra Kaew). It is also considered one of Thailand's most sacred sites.
Definitely try to go as soon as they open to avoid the heavy crowds, but just know it can be an extremely crowded tourist attraction no matter when you go. We were completely engulfed in a sea of people and umbrellas almost instantly which can be overwhelming. It is also really hot, so bring water, and girls need to cover their shoulders and legs, while guys need to wear pants.