This tome looks like a haphazard collection of random notes on different types of paper stitched together and bound within a wooden cover. The pages describe all of the 300,000 gods of the world, each in the language of the people who worship them. The book is stored high in the mountains, kept safe by an order of monks. Reading the entire book confers a deep understanding on the nature of the cosmos and access to incredible power. This only works, however, if it is read without translation, meaning that the reader must master each language contained within. The various monks know these languages but there is typically only one alive at a time who knows them all. This monk would be an excellent source of information and/or magic. IF the PCs learn about it; IF they can find the monastery; IF they can convince the monks to help them; AND if they can understand the convoluted riddle given as an answer.
A small, enchanted chest, 2 feet on a side. It is of some dark wood with fantastical images graved upon it. Worn leather straps act as hinges and a simple toggle keeps it closed. Anything placed within it, with the lid closed, becomes accessible to anyone with one of the other 5 identical chests. Once it is taken out of any one of the 6, the chest is empty again. Perfect for passing messages or small items between widespread groups, such as ships at sea and their ports of call or generals on the field of battle.
A cave with weapons sunken into the walls, blades sticking out of the floor and ceiling, and so on. Possibly, any weapon used in it could be torn out of the hand and sink into the stone.