Many megaprojects have been proposed to connect landmasses with bridges, tunnels or a combination of both. These proposed crossings could bring significant benefits, but face engineering, economic and geopolitical challenges.

An answer will resolve YES if at any point before 2051, a fixed link exists between the two locations that is open to the public. This could be a bridge, a tunnel, or a combination of both (using natural or artificial islands, e.g. a bridge from Scotland to Isle of Man and a tunnel from the Isle of Man to Ireland would count as a crossing from Great Britain to Ireland, even if these were built separately), and can be for rail, road or any other form or forms of travel. Answers will immediately resolve YES once the crossing is open, even if it subsequently closes.

The answers refer to geographical locations, and an answer can still resolve YES if there are different countries in control of the ends of the crossing than those named.