Angkor Borei is a small settlement on the banks of the Prek Angkor, containing Funan ruins thought to be up to 2000 years old. There is not much of what used to be an ancient walled city left today. The nearby museum ($1) has various artefacts from the ruins, giving you an insight into what the place would have looked like. The best part about visiting here is undoubtedly the 45min boat ride from Takeo along the canals. It's a great way to see the rural riverside living. In the wet season when the water levels are high enough you can continue to Phnom Da, a square tower temple at the peak of one of two 45m adjacent hills. The foundations of the temple were built in the 6th century, but most of what you see was rebuilt in the 11th century. Most of the precious artefacts have been substituted except on the east side. There are four caves on the way up to the temple that have been used as Hindu and Buddhist shires, as well as hideouts by the Viet Cong. When the waters are not high enough you can get here by moto from Angkor Borei. Phnom Da and Angkor Borei can be done as a day trip from Phnom Penh, and there are many tour agencies in the city that will arrange this for you. The National Highway 2 to Takeo is in reasonable shape if you want to bike here. Alternatively, you can stay in Takeo and any guesthouse in town will be able to arrange this trip for you.