A tower isn’t just decorative — height gives you visibility over your base and the surrounding terrain, which makes spotting mobs (or players, if you’re on a server) far easier.
Step 1: Lay the base
Mark out a 4x4 footprint and build straight up 16 blocks. Keep the walls solid — this build’s strength is in being a simple, unbroken column.
Step 2: Add a ladder
Run a ladder up one interior wall from bottom to top. It’s slower than stairs but takes up far less interior space, which matters at this footprint.
Step 3: Light every few levels
Place a torch every 4-5 blocks as you go up — both to prevent mob spawns inside and to stop the interior looking like a pitch-black shaft.
Step 4: Cap it
At the top, add a fence-post railing around the platform and, optionally, crenellations (alternating raised blocks) around the edge for the classic watchtower look.