There are quite a few attractions visitable as day trips out of Bangkok, most easily on tours that may combine two or three of them in one day. Perhaps the most popular trip from Bangkok is the 109km journey southwest to the picturesque Damnoen Saduak Floating Market (ตลาดน้ำดำเนินสะดวก) in Ratchaburi province. This market is very popular with tourists, though it is still a little better than the one near Wat Sai in Thonburi. The main floating market on Khlong Damnoen Saduak (Damnoen Saduak canal) is Ton Khem market, but there are others at Hia Kui and Khun Phitak. Hia Kui is the most touristy and has boats mainly of souvenirs for tourists but others are not quite as bad. Really, it would be hard to justify any trip to the Floating Market if it wasn't for the fact that Bangkok is famous for them.
Most people come here on a tour but it really is best done independently if you want to avoid the crowds. It takes place in the morning and tours tend to arrive at 9.30am, so those who arrive by 9.00am or earlier will have the best experience. This also leaves you free to hire a boat yourself and look around the canals and markets, this costs about 300B an hour. To get there early, take one of the buses from Bangkok's southern bus terminal in Pin Klao - They start at 6.00am, go every 20 minutes or so, cost around 50B and will normally take about two hours. Alternatively, there are a couple of hotels in Damnoen Saduak itself.
Tours to Damnoen Saduak will very likely also visit the Rose Garden and the chedi at Nakhon Pathom. The Rose garden is set in large landscaped tropical gardens but is mainly visited for the 'cultural show' that's put on there - Thai traditional dance, Buddhist ordination ceremony, muay thai (Thai boxing), elephants at work, takraw (a common sport in Thailand) etc...It's totally touristy and as contrived as can be, but if you know what you're in for it can be reasonably entertaining nonetheless. Also in the grounds is a luxury riverside resort, thousands of rose bushes and hundreds of exotic birds. Close to Rose Garden are the Thai Human Imagery Museum and the Samphran Elephant Park. The human imagery museum is a Thai Madame Tussauds with images of famous monks, all the Chakri dynasty kings etc...This is really aimed at Thais rather than foreigners. The Elephant park has a variety of elephant and crocodile shows (wrestling, tug-of-war etc..)
Nakhon Pathom (นครปฐม), around 60 km west of Bangkok, is a town famous as the reputedly the oldest in Thailand and the place where Buddhist missionaries first entered Thailand from India. Nowadays it is a fairly typical provincial Thai town with only the gold encrusted Phra Pathom Chedi (พระปฐมเจดีย์) hinting at it's celebrated past. This is a massive 127m high, making it the word's largest Buddhist monument, and the most important in Thailand. As well as the main chedi, there are numerous bots, Buddha images and other structures nearby. There are hotels nearby, but this is mostly visited either on a tour from Bangkok or on route to Kanchanaburi.
