We stayed there in 2018, very good stopover, the wheel is a wonderful sight in the morning mist, and at night,Hi...it's the car park at The Falkirk Wheel. £15 for 24 hrs. Fresh water...rubbish bins..grey waste and use of toilets during the centre's opening hours. Never been before but impressed.
The Kelpies are another good place to visit and stop overnight as well,