Backpacks allowed in Mayan Ruins in Tulum?

Hi all,

We are going to the Mayan Ruins in Tulum next week and wanted to know if backpacks are allowed? We figured we need to bring water bottles, sunscreen, snacks, etc., so a backpack would be very helpful. If anyone knows, I’d appreciate your insight!

Also, if backpacks aren’t allowed, what about cross body bags?