Four new dungeons are available to download on the Pokémon Mystery Dungeon: Gates to Infinity 3DS game. Available through the game's DLC feature, each dungeon ranges in price from two to three dollars each (USD). Don't worry if you don't see some dungeons at first; they'll appear once you've beaten the game. Here's a summary of each dungeon, straight from the official site:
Take a trip through the Axe Rock dungeon to encounter many Axew. Axe Rock is also a great place to level up your moves and track down lots of good items! Be sure to return to the dungeon after you beat the main story for even better opportunities to explore its depths!
Befriend many Tepig when you explore the depths of Mount Tepid! This 12-floor dungeon is filled with the Fire-type Pokémon, as well as plenty of good items for you to collect. Don't forget to look for a Fire Device, which will permanently boost the stats of the Fire-type Pokémon you give it to.
In some dungeons, you need to keep your Belly full. Discover a new type of food that's great for those dungeons: Donuts! Explore Treat Road and find exclusive Mini Donuts, Donuts, and Big Donuts that will keep your Pokémon's hunger at bay. Your Pokémon will also earn Exp. Points when they eat the Donuts you find along Treat Road.
Prepare for another stupendous challenge when you enter Strongest Trail, a 60-floor dungeon filled with some of the toughest Pokémon found anywhere! If you can make it all the way through Strongest Trail, you'll be rewarded with the exclusive Persistence Crown!