We have spent many months travelling around Thailand and found Kanchanaburi to be a delightful part of the country. In particular it offers visitors a wide choice of attractions many connected with the events that took place in and around there during the Second World War.
If you do visit Kanchanaburi, we would recommend:
Kayaking down the Kwai (but do the long version 12 km) – you can rent a kayak, they will drive you out of town – up stream, and you paddle or float back downstream to the town. The scenery is fantastic, you can normally see some wildlife along the river edge, and you can stop at a couple of the resorts on the way downstream for a beer or soft drink.
The waterfalls at Erawan National Park. Seven waterfalls along this stretch of the river. The water is crystal clear and there are a number of swimming opportunities. Be aware that you should wear good water shoes for this trek.
Elephant trekking. If you like elephants, this is a great trip out. A couple of companies combine this with a short river rafting trip and this too is a great adventure.
The war cemetery in the town should be visited and respects can be paid to some of the thousands of men and women from the allied forces that died here during the Second World War. And, of course, you cannot come here and not visit The Bridge Over The River Kwai.
Hellfire Pass. We think this is the best of the museums though it is not a museum in the true sense. This is the site of the Konyu cutting - a particularly difficult section of the Thai – Burma railway. Many tens of thousands of pow’s died in its construction and the very emotional story of the men that lived and died here in told very well. Some trekking is involved in this tour so wear reasonable walking shoes. If you are on an organized trip, ensure they allow a good 2 or 3 hours here.
Of course, if you do spend a day or two in Kanchanaburi, it does not mean that your stay on Koh Tao should be cut short to compensate. No way man. You will find out why once you get here. So instead you will just have to extend your trip a little. You were born to endure such hardships.