How to Build a Lighthouse in Minecraft

Guide Java Bedrock

Quick answer: Classic lighthouse: a striped tower 5x5 at the base tapering to 3x3, 20-30 blocks tall, red-and-white (or black-and-white) bands every 4 blocks, a glass lamp room on top with a sea lantern or beacon inside.

What you need

White and red concrete (or white/black) - 8-10 stacks total
Glass panes for the lamp room
A sea lantern, glowstone or beacon for the light
Slabs and fences for the gallery

Step by step

Site it on a rocky point or a tiny island - lighthouses need water. A stone foundation 2 blocks above the sea keeps it dry.
Base: a 5x5 or 7x7 footprint, first band 4-5 blocks high in white concrete.
Alternate bands: 4 blocks white, 4 blocks red, up to 20-30 blocks total. Taper the last band to 3x3.
Interior: a spiral stair of slabs around the wall works even in 5x5. Windows every other band, one block wide.
The lamp room: glass panes on all sides, a sea lantern or glowstone in the center, a slab roof one block wider than the room.
Gallery: a fence-railed walkway around the lamp room - one ring of slabs outside the glass.
Want a real rotating light? A beacon on top shines to the sky and marks the coast from anywhere.
Finish the scene: a small keeper's hut, a dock with a boat, and a couple of lanterns on the rocks.

Java vs Bedrock

Identical on Java and Bedrock.

Versions: Sea lanterns and beacons work the same in all current versions.

Frequently asked questions

Beacon or sea lantern for the light?

A beacon's beam is visible across the map - the true lighthouse effect - but costs a Nether star. A sea lantern looks better up close. Many builds use both: lantern for looks, beacon for the beam.

How tall is too tall?

20-30 blocks reads perfectly from the water. Taller starts needing a wider base or it looks like a stick.