Magnetic Hill is the famous Ladakh roadside illusion where vehicles appear to roll uphill against gravity. The effect is caused by the surrounding slope and horizon confusing your sense of level, but that explanation does not stop people from testing it.
The stop is touristy, and it should not be oversold. What makes it worthwhile is the setting: a stark ribbon of road, bare mountains, and the fun of a small shared experiment in one of India's most dramatic driving landscapes.