Christopher West is well known for his sci fi and fantasy maps and mini-scale map work, including a lot of work with Paizo. He put out 3 fantastic dungeon/drow-themed maps a few years ago, called Deep Vistas, and currently has a Kickstarter going to produce a 4th map in the series. It'll be $15 when funded and is well worth the money.
Link: Deep Vistas IV
If you're a little leery about getting involved in a Kickstarter campaign, don't be. Christopher has run a bunch of very successful campaigns, has all the artwork done in advance, and always delivers an amazing product within a few months of the project funding. He really just does the Kickstarter to cover production costs so he doesn't have to pay it all himself upfront. Seriously, zero risk.