The Giant Swing was something that I came across more than aimed for if the truth be told.
I understand that it was built in 1784 and was traditionally used in swing ceremonies - an annual swinging ceremony known as Triyampavai-Tripavai was held at Giant Swings of major cities until 1935. I think that it is a Hindu Ceremony?
If you visit the Bangkok National Museum (พิพิธภัณฑสถานแห่งชาติ พระนคร) they display the original timbers that were used for this. Surrounding it are places which you must visit - Wat Suthat Theo Wararam, Tiger God Shrine, Deasathan and more