Kbal Spean is a riverbed with many Hindu carvings. All very poignant, meaningful and pretty but we were really heading there for the waterfall. After what seems 8h of tuk-tuk we stretched our legs with a shortish (1.5km), mostly uphill, hike to the river. The kids did pretty well - soon we got into a pattern of 100m walking / 100m carrying (there are signposts every 100m so flabby tourists don't loose hope).
Ta Prohm was also on the list for today but it was getting late. Temples open at sunrise (5:30) and close at sunset (17:30-18:30). We'll have to ave it for tomorrow.
Lesson learnt today: no matter how far you go out from Siem Reap you can't beat the crowds - the only way is to get the timing right.