D&D General good dungeons to populate a sandbox setting?
Orius
Legend
The Shattered Circle is a favorite of mine from late 2e, it's a decent sized dungeon that is easy to just plug and play into the campaign, and it has some reusable aspects to it.
If you like the classics, don't forget B4 The Lost City. You can expand the dungeon from the basic 5 level setup to 10 levels, or even expand down into the underground city below and even further if you want to link the catacombs to the Underdark. Of course it is in a desert setting so it probably will be harder to link up with Saltmarsh, but it is one of the classics for a dam good reason. Possibly you and your group have tackled that one though.
If you like the classics, don't forget B4 The Lost City. You can expand the dungeon from the basic 5 level setup to 10 levels, or even expand down into the underground city below and even further if you want to link the catacombs to the Underdark. Of course it is in a desert setting so it probably will be harder to link up with Saltmarsh, but it is one of the classics for a dam good reason. Possibly you and your group have tackled that one though.
I'm a big fan of the Hyqueous Vaults (3rd level adventure written for OSRIC), and it seems like it would be a good fit for your hexcrawl. The PDF is free on Lulu.
The Pathfinder adventure path Ruins of Azlant is set on an uncharted island, with opportunities to travel to nearby islands as well. I'm currently playing in it, so I haven't read it, but so far (parts 1 and 2) it has been great fun. It has lots of small dungeons dotted about the place and seems like it could easily be repurposed as a sandbox by throwing out the metaplot. (Admittedly the price per dungeon might be a bit high afterwards, so maybe not good value for money.)
The Paizo adventure Crucible of Chaos (for 3.5 edition) involves an interesting exploration of a crashed flying city. I'd be very tempted to include a method for the PCs to get it back flying again (for a short time, anyway), allowing them to access places they otherwise couldn't reach.
The 2nd edition adventure Evil Tide has an interesting dungeon in it and the plot is easily removed.
Barrowmaze is a megadungeon, so not what you are looking for, but if you happened to own it already then the above ground environment and "lesser" burial barrows can fit nicely in a sandbox without needing to include the main dungeon.
The Pathfinder adventure path Ruins of Azlant is set on an uncharted island, with opportunities to travel to nearby islands as well. I'm currently playing in it, so I haven't read it, but so far (parts 1 and 2) it has been great fun. It has lots of small dungeons dotted about the place and seems like it could easily be repurposed as a sandbox by throwing out the metaplot. (Admittedly the price per dungeon might be a bit high afterwards, so maybe not good value for money.)
The Paizo adventure Crucible of Chaos (for 3.5 edition) involves an interesting exploration of a crashed flying city. I'd be very tempted to include a method for the PCs to get it back flying again (for a short time, anyway), allowing them to access places they otherwise couldn't reach.
The 2nd edition adventure Evil Tide has an interesting dungeon in it and the plot is easily removed.
Barrowmaze is a megadungeon, so not what you are looking for, but if you happened to own it already then the above ground environment and "lesser" burial barrows can fit nicely in a sandbox without needing to include the main dungeon.
Tales and Chronicles
Jewel of the North, formerly know as vincegetorix
Oh, I forgot:
you could also take the elemental temples from Princes. Just remove the passages that connect them all together. Maybe each haunted keep has a gem, key, rune or whatever to unlock the elemental forcefield that block access to the real temple somewhere else on the map.
From CoS, I'm a big fan of the Death House and Ol'Bonegrinder. They are not much in the sense of dungeons, but the theme behind them is a nice change of pace.
you could also take the elemental temples from Princes. Just remove the passages that connect them all together. Maybe each haunted keep has a gem, key, rune or whatever to unlock the elemental forcefield that block access to the real temple somewhere else on the map.
From CoS, I'm a big fan of the Death House and Ol'Bonegrinder. They are not much in the sense of dungeons, but the theme behind them is a nice change of pace.
Tomb of Annihilation has several smaller dungeons like Wyrmheart Mine that I think could work in any campaign. But if you have an archipelago of jungle islands, then the Chultan temples and ruined cities are an even better fit. So I'd definitely suggest that book.
Curse of Strahd has amazing maps that can be reskinned with moderate effort. Towns, bridges, caves, temples, mansions, etc. It's got it all.
Finally, I'd suggest picking up Scourge of the Sword Coast and Ghosts of Dragonspear Castle from the D&D Next playtest. Like the above examples, it has a plethora of excellent maps.
Curse of Strahd has amazing maps that can be reskinned with moderate effort. Towns, bridges, caves, temples, mansions, etc. It's got it all.
Finally, I'd suggest picking up Scourge of the Sword Coast and Ghosts of Dragonspear Castle from the D&D Next playtest. Like the above examples, it has a plethora of excellent maps.
The Ruins of Rhest chapter from the Red Hand of Doom may be easy to insert. A conflict is rising between historically savage but local lizardmen and the nearby wild elven tribes. A dark evil broods in the lake and organizes their activities. The party needs the elves' assistance on a greater outside threat of some kind but won't be able to get the elves' assistance if they don't deal with the local problem so the elves are secure enough to send troops abroad.
WayOfTheFourElements
Hero
UK1: Beyond the Crystal Cave is an odd little dungeon. All the combat encounters are optional. Perfect for druid characters.
X2: Castle Amber is a blast if insane wizards are your thing.
X2: Castle Amber is a blast if insane wizards are your thing.
Tales and Chronicles
Jewel of the North, formerly know as vincegetorix
Oh, what a great idea: use the 9 temples of the false gods as small puzzle dungeon to dot the map. Maybe if you get them all, you can unlock a super cool dungeon with nice loot. You can get a nice Legend of Zelda vibe whit that!
Lanefan
Victoria Rules
It's a coastal/maritime setting, so two obvious ones are X1 Isle of Dread (even pre-fits the tropical theme!) and L1 Secret of Bone Hill if you put Restenford on an island. When I ran Ghost Tower of Inverness I stuck it in a swamp, and this worked fine. Tomb of the Lizard King is pre-set in a swamp if memory serves.
And you can stick Castle Amber and JG's Tower of Ullision anywhere; swamps do have a lot of fog...
@vincegetorix - you beat me to my next suggestion, so I'll merely second your idea about breaking up Princes of the Apocalypse into little standalone dungeons (and maybe refluffing the story for each; nothign says they have to be connected), and those dungeons could be plopped down in/under any surface setting.
In fact that's why I bought PotA in the first place: I saw it as getting 15-ish adventure modules for the price of three!
And you can stick Castle Amber and JG's Tower of Ullision anywhere; swamps do have a lot of fog...
Thing is, nothing about B-10 indicates anything remotely maritime; and some of those adventures are set in high hills or mountains. It'd take some serious re-skinning to shoehorn all that into a tropical coastal-forest setting; the goblin lairs would be trivially easy, the rest maybe not so much.
@vincegetorix - you beat me to my next suggestion, so I'll merely second your idea about breaking up Princes of the Apocalypse into little standalone dungeons (and maybe refluffing the story for each; nothign says they have to be connected), and those dungeons could be plopped down in/under any surface setting.
In fact that's why I bought PotA in the first place: I saw it as getting 15-ish adventure modules for the price of three!
Tales and Chronicles
Jewel of the North, formerly know as vincegetorix
In fact that's why I bought PotA in the first place: I saw it as getting 15-ish adventure modules for the price of three!
I even forgot to note that the side trecks at the end of the book are also nice little adventure sites.
