Without a doubt, all the main areas of interest within Kanchanaburi city can be explored without recourse to a tour. Many of the interesting places, from the Bridge to the museums to war cemeteries, can be visited on foot or bicycle which can be rented from almost any guesthouse. Armed with a map and maybe some helpful advice from your guesthouse staff, you should be able to find most of the sights without any problems, and if you stay in the popular riverside / Mae Nam Kwai Road area you will find plenty of fellow travellers who can advise you. You can always hire a tuk-tuk or jump on one of the regular busses to take you to the more distant spots. If you want to try going it alone up-country, here is a suggested route. Start at around 10:00am and catch any Sangkhlaburi-bound bus from Kanchanaburi, ask the driver to drop you off at Nam Tok. The journey will take about 90 minutes. Make the short climb from the bus stop to the Sai Yok Noi waterfall. Although the falls now splash into a made-made pool, it's still an enjoyable sight with many families out to enjoy themselves for the day. The old train station nearby has been converted into a restaurant, and is a good place to have some lunch. You'll then need to go back down the road a few hundred metres to the road that leads away from Route 323. Follow the signs to the main train station, a distance of 2km. Take the 1:00pm train back towards Kanchanaburi. The first part of the train journey passes through bamboo woodlands, and you can see distant temples far away on the hill-tops. Then the track goes out onto a ledge high above the river, with great, but quite scary views. Get off the train at Tha Kilen station and follow the road away from the station, then take the first right. A short walk will bring you to the Khmer temple of Prasat Muang Singh. The site is the furthest point that the Khmer empire extended to in the west, and it's now a lovely tranquil setting. The well-restored ruins present a sharp contrast to the untouched, Khmer ruins, often in overgrown settings that you find elsewhere in Thailand. These temple grounds are generally ignored by tour groups, so you will have the place to yourself. The next train will stop at around 2:25pm, so you have an hour to explore the ruins before you head off again. You'll have another hour on the train before you reach the River Kwai Bridge and onwards to Kanchanaburi. You've spent the day with no organised tours and no crowds, and you've seen some sights that many never knew existed.