Currently reading: Underland: A Deep Time Journey by Robert Macfarlane, which is a bit weird to be reading right now because I only just recently read Underground: A Human History of the Worlds Beneath Our Feet by Will Hunt; and Gods of Jade and Shadow by Silvia Moreno-Garcia, whose Signal to Noise I enjoyed. You can browse my highlighted passages from these books, although it takes a bit of scrolling.
Because the world thinks it’s clever, the section of Underland I last finished talked about limestone, the Yucatán, underground rivers, cenotes, and Xibalba. So, naturally, the chapter I just began in Gods of Jade and Shadow opens by discussing Yucatán limestone, where “[w]hat rivers there are run underground, secretive in their courses”, cenotes, and Xibalba.