Two that I found very easy to understand just from the battle maps were the Emerald Spire and the Abomination Vaults, as both have a central recurring feature to orient yourself by - the titular spire and the Gauntlight’s beam. It makes them a lot less sprawling than many classic megadungeons, but also lets me and the players easily work out how everything connects just by comparing its position to the central feature.
Two that I found very easy to understand just from the battle maps were the Emerald Spire and the Abomination Vaults, as both have a central recurring feature to orient yourself by - the titular spire and the Gauntlight’s beam. It makes them a lot less sprawling than many classic megadungeons, but also lets me and the players easily work out how everything connects just by comparing its position to the central feature.