No no no! It is not really a “lighthouse” of those that guide ships, it is a light that you can use to decorate your castle and to have extraordinary powers!
The beacon is a single block that projects a beam of light into the sky and can provide status effects to nearby players.
The headlight can be obtained by breaking it with any tool or with your hands.
The headlights have two functions:
An aesthetic mark that reaches the ground and can be seen from far away, if it is on a 3×3 surface (see Beam of light).
Power source, providing effects to the player if they are in range (visual beam must be activated)
To activate a beacon the following requirements must be met.
On the surface it must be in the open air (water, glass or other headlights do not count as obstructing blocks). In the Nether or End ignore blocks from Y = 128 onwards (see MC-73406), but need an unobstructed path to that level. As a consequence, a lighthouse cannot be activated in the Nether without cutting a path in the bedrock (see MC-67727).
The lighthouse must be at the top of a pyramid of iron, gold, emerald, diamond and / or subterranean blocks.
beam of light
When activating the lighthouse, a beam of light emerges from it, this extends to Y = 255 in the Overworld and up to Y = 127 in the Nether and the End. The beam is visible from afar as if it were a block. If the render distance is 16 chunks, the light beam will be seen from 255 blocks away.
The beam color can be changed by placing tinted glass (or tinted glass panels) at any height of the beam. The first color will be pure, but the others will result from mixtures between the other colors. The mechanics are the same as for the dyes.