The people in Lisbon at the moment for the World Esperanto Congress won't be able to avoid the São Jorge Castle, the citadel which looms over the city:
Esperanto has its own castle, around 250 kilometres southwest of Paris. It's called Kastelo Greziljono, Château de Grésillon in French.
The property is owned by a co-operative of Esperanto speakers and has been used as a Kulturdomo de Esperanto (Esperanto Cultural House) since 1951. The non-profit team hold residential courses throughout the year, including several for beginners and new learners.
So, once you've finished with Complete Esperanto and fancy immersing yourself in an Esperanto environment, you might fancy participating in one of the courses run from Greziljono with other beginners. You can find details on the kulturdomo's site.