Tonlé Bati is the collective name for a pair of old Angkorian-era temples and a popular lakeside picnic area. It's worth a detour if you are on the way to Phnom Tamao and Phnom Chisor. You can eat at one of many picnic restaurants here and hire an innertube to float around the lake for 2000r. Just avoid Tonlé Bati at weekends, when it's mobbed with locals.