Reposting to Tulum forum.
Group: two parents, avid walkers, and 19 year old Spanish studying, near-fluent daughter, interested in beach and eco-tourism. Looking for spot in Tulum congenial to all, but preferential to daughter (trip is birthday gift).
Time: early to mid May, 5-7 day trip, depending on cost.
Budget: $4,000, complete, not including airfare.
Restrictions: Don't want to change hotel more than once, or spend a great deal of time on ground transportation. Want a walkable area, relatively crime free area.
Thank you, 'pepper', for suggesting Cabanas la Luna. Turtle viewing nearby in May?
Other suggestions for lodging and activities appreciated.