This is one activity in Los Cabos you simply cannot miss. Plan an ATV (All Terrain Vehicle) tour for earlier in your stay, as you will surely want to do it again! We made the mistake of making reservations to do this on the day prior to our departure.
We signed up for the "Old Lighthouse Tour." After our group of about 20 people received a brief orientation of how to operate the ATVs, we took a short ride up to a ridge of dunes . . . and once over that ridge there were expansive, pristine dunes over looking the Pacific Ocean. On the other side of the ridge, there were desert trails of varying degrees of difficulty that you could explore to your liking. For two hours, you'll gleefully bounce your way over these beautiful dunes and trails. You can also investigate the "Old Lighthouse" located on the beach. Take your camera (we didn't and regretted it!). It was LOADS of fun . . . the guides were great, and the ATVs are easy to handle once you get the swing of it.