Sometimes cross country cycling competitions are held at Pulau Ubin during the weekends, and you have to be careful when walking along the paths which are used by the cyclists. They are rather fast and may collide with you at very fast speeds.
No trespassing and no rock climbing. Swimming in the are prohibited. Trespasser will be refered to the police and fine SGD1000.
We were told that the ancester of wild boars had bad experience on round thing. So the displayed wheels are looked like a hole which can prohibit the wild boars to come nearer to the domestic animal.
Be careful not to go near the mangrove swamps and rivers. There were previous cases where people were drowned after falling into the fast flowing water of the rivers of Pulau Ubin.