If you're looking for Diablo 4 cellar locations, then I bet you're on the Holding Back the Flood step of the season questline. Most of the activities in the Season Journey chapters are fairly quick or easy to do, while you'll get a few that might take a bit more time, such as doing a certain number of dungeons, or—perhaps unsurprisingly to you if you're reading this—completing 10 cellars.
Diablo 4's first season sees the arrival of a curse that has infected Sanctuary, turning enemies and humans into stronger and more bloodthirsty versions that drop Malignant Hearts when killed. The new quest line, centred around combating this curse, takes place after the main Diablo 4 story, so if you've reached the point where you need to start ticking off Season Journey chapter objectives, here are the Diablo 4 cellar locations.
Diablo 4 cellar locations
Cellars are found all over the map in Sanctuary but you can only see them on the minimap when you get close to the entrance—unlike dungeons, they don't show up on the big map at all. The only exception to this is when a particular cellar is one of the objectives for the Tree of Whispers and awards Grim Favors for completing it.
Cellars are like mini-dungeons and they only take a minute or two to complete. They have one main room and you'll need to complete some sort of objective which usually involves killing a boss and looting a chest. Generally, you don't travel far without spotting the entrance to a cellar on your minimap, and you're probably used to ignoring them for much of the time. Of course, the minute you need to find one for a specific quest, you can guarantee you'll run around for ages without finding one.
Thankfully, there are interactive maps like Mapgenie that can help you locate hard-to-find items or objectives. For Diablo 4, this is likely to be the most reliable way of finding the 10 cellars you need for the chapter objective. You can check the approximate locations of the cellars in the screenshot above.