Minecraft wiki entry for Exploring_an_ancient_city, associated text: Simply put; make sure that you have a safe escape route ready and available, ideally one that leads all the way back to the surface. After that, make your way into the city (by sneaking) and then simply start breaking every Sculk Catalyst, Sculk Sensor and Sculk Shrieker you can find. This will cause an absolute cacophony of noise and will surely cause the Warden to spawn in short order. In that case, you simply need to turn around and quickly begin making you way towards the exit mentioned earlier, distracting the Warden away from you as needed, and once far enough away, leave the Ancient City and wait for about 60 seconds to allow the Warden to despawn (ideally you should wait a bit longer to account for potential delays). Once the Warden has despawned, you may safely return back and start breaking Sculk Sensors and Sculk Shriekers again, and leave once again when the Warden appears and returning once more when the Warden has despawned again. By repeating this cycle continuously, then as long as a Sculk Catalyst does not generate any new Sculk Sensors or Sculk Shriekers, the Ancient City will eventually run out of them in the long run as the player gradually breaks them all one by one.