Here is the official explanation of what the Activity is looking for – builders should share their builds on the very same page it has been announced:
A famous landmark on an 8×8 baseplate. Go!
This is part of a series on LEGO Ideas that gives little tasks for builders to get involved with – there are no prizes, they are just a way to get involved with building something quick for fun. Each challenge is intended to be something quick and fun, unlike the more in-depth building required for a competition or product idea.
The deadline for this Activity is September 22 at 10.00am CEST.