I did The Jungle Challenge myself. And it was very funny sometimes. It was my own idea, but maybe the Challenge exists already. (Add ons, that you need: Outdoor retreat)
Here are my rules:
-You should buy a 50x50 lot.
-Only one sim should live there and this sim mustn´t leave the lot. No other sims are allowed to go on your lot, because it should be an island.
-Around the lot there is a pool. (It´s helpful to install the mod to get hygiene from swimming. http://modthesims.info/d/555571 )
-And there are trees. You must place the Forgotten Grotto and Sylvan Glades on the lot (Also a place for fishing) (By tiping: bb.showhiddenobjects )
-You must place a workbench, a tent and a fireplace in your house inventory.
-First you will get the workbench. After a time you will take the other things. You must build all things with the workbench (not the tent and the fireplace)
-When you will have reached level 10 of the Handiness Skill, other sims can visit you and you must start a family.
-Now you can decide, if you live your quite life at the island and about more generations or if you go back to your home and live like a normal family.

I hope, you`ll like the challenge (maybe you know about it already). Sorry for my (maybe) bad english...

I played something similar a while back but it was with a bunch of sims-I like your Idea. Think I 'll give it a try.
I'm not clear on when we get the fireplace ?
thanks


ok I can't figure out how to place the glade or the grotto. help Please

Hmm, sounds kinda like a challenge I've done before but a little more laid back. Totally trying this!

I know this is a few months later and I don't know if you ever figured it out. You need to enter the cheat command bb.showhiddenobjects and then in build mode search for "debug". Show all items. It is quite an extensive list and you'll havta do a bit of searching, but the grotto, glade and even ponds can be found in here.