There's an amazing variety of dungeon board artwork available nowadays.
We wanted to dungeon dive, but not spend a ton of time and money making full 3D terrain.
The compromise: make 2 and a half - D terrain, cutting out floors and walls and mounting them on Foam Core to represent different levels.

We're really happy with the Heroic Maps Great Dungeon tilesets, since you can lay out lots of different variants very quickly.  It took about two months to make 2.5D versions of all these tiles...

We even made some tiles with cutouts in the floor, allowing us to put different backdrops below for a variety of effects.

They even have a nice Cave Tiles set (although the connection points are a different size).

Our other favorite source for dungeon board art is Seafoot Games.  These large boards are not modular, but look great.  It's a bit more work to make 2.5D versions of these boards, but thankfully most of them fit well on the 20x30 inch foamcore you can find at Dollar Tree stores.  (You just have to paint the edges of the foam core black for best results).

This 2 level crypt was one of the first boards we played on in our campaign.

This undersea Ruins board has lots of areas to explore- once you figure out a way to breathe underwater...

This massive coastal town required FOUR 20x30 foamcore boards and barely fits on our table.   We use the boards for our town of Scrimshaw.


The next board was also a huge 4 panel project, this time a lengthy bridge with 2 levels to explore.

Here you can see how the top levels are cut out to fit on top of the lower levels.  There were so many wooden walls in the lower section, we made them 2.5D with strips of Balsa wood instead of trying to cut so many thin slivers of foam core.   A quick pass with furniture touch-up markers gave the walls a deep wood color.

This two panel Jungle Temple ruin with a river running through the center is a great layout to explore.

These shoreline cliffs are dotted with ruins and interesting paths to traverse.

This 2 panel Manor infested with fungus was a great location for one of our ghostly NPCs.

Be sure to check out our 3D terrain too!