Golestan Palace is probably the most popular place to visit in Tehran. It literally means the Roseland Palace. The palace is a former royal Qajar complex in Tehran, which Kings of Qajar lived there. The area was huge, with a number of of different galleries and museums throughout. It is located in the center of Tehran, with a short walk from the Grand Bazaar and Park e Shahr, which made it the first choice to visit when I first arrived in Tehran.
What I love most was its huge and beautiful yard, especially those colorful decorative mosaic walls around the palace.