Just a quick review. I agree with pretty much everything Rachel B. said, and the fact that you get all these unique environments and ideas plus 7 soundscapes...very good bargain. If you use the Forgotten Realms campaign setting you can plug these environments into a new (undiscovered) large section of Undermountain, or even underground areas in Chult or Maztica (though perhaps swap out a few of the inhabitants for those areas). It could be a pocket dimension or the beginning to some other plane of existence. There's plenty more ideas you'll discover on your own as your read through this unique accessory, and I recommend giving it a try.

This is a nice location kit with an attractive layout, pretty maps, and atmospheric music. The pages are packed with text. Each area is detailed with multiple ideas for monsters, healing ideas, and treasures you can adapt to your world.

The maps are very nice and are indeed quite large. There are both GM and player copies. I plan to print the player copies out into several sections to lay down as needed and keep the GM copy on my tablet.

Everything is very system-agnostic - even the area descriptions are written to the GM, not in a narrative style. You should expect to be writing your own narration and plot line. That's great for customizing your own campaign and making it special for your own play group. Just don't expect this to be ready-to-play. This is a jumping off place.

If you like background sounds for your campaign - and I do - that's a place where this pack really shines. There are sounds for each general area, and they are generic enough to be useful in many campaigns but detailed enough to provide real texture. They are also nice and long. Your players probably won't notice them repeat.

I also want to give a big shout out for the great customer service. When I asked the publisher for assistance with the game, I had help within an hour. Huge props for that. For that above all I will definitely be following this publisher.