We all know that a happy combination of luck, aggression, predestination and geography causes the base meridian of longitude to go through Greenwich. In earlier times there were several others: Paris, Copenhagen and Berlin all had "their" meridians but we won out (anyway, wouldn't it be stupid to call something the "Greenwich Meridian" if it went through Berlin or Copenhagen?). Incidentally, the French clung on to their Méridienne Parisienne well into the 20th century, silly lot. There is
some interesting psychogeography
to be done in following it.
Knowing that it goes through Greenwich is useful, but where else? France, plainly (but not through Paris 😀), but where else? Google to the fore, we can draw a circle that goes from pole to pole and back, following the 0° and 180° meridians (Click to enlarge, obvs.).
No surprises that the majority of this is sea (counting the arctic as sea, which it is). The 180 meridian intersects very little land (all Russia), and the 0 meridian is just wet in the southern hemisphere. There are, however, four countries which intersect twice.
The UK
Maybe it's cheating to consider the Humber Estuary as an interruption - make your own mind up. The meridian just misses Flamborough Head, but if were visible, you'd see it.
Russia
Given its size one cannot be surprised that Mother Russia figures in the list. Off the north coast of Siberia (north of the 70° parallel) lies
Wrangel Island
[О́стров Вра́нгеля]. The Island was named by a Briton after a Russian Admiral who was German, but it has a variety of other names derived from languages more appropriate. It is designated in its entirety as a "nature reserve", which might mean anything in modern Russia.
There is a great deal to be read about this place; it was home to the last surviving woolly mammoths on earth.
Spain
The shape of Spain's Mediterranean coast provides a 30Km (or so) land intersection just south of Valencia. Pleasingly, the Meridian exits toward Africa at
Marina Greenwich.
Togo/Ghana
When those Imperialist bastards decided where to draw national boundaries in Africa, they plainly decided to have a laugh when it came to Togo. Leaving Burkina Faso, the Meridian enters Togo, leaves it, enters it again (from Ghana), then leaves it back to Ghana and onward to the seaside.
The first Togo stretch is about 2Km long (my estimate - it really isn't easy to get precise measurements from Google).
The second stretch is rather longer, at something like 30Km - again, rather approximate.
I have searched in vain for images of the Meridian meeting/leaving Togo, thus far with no joy. Any I receive will be posted here without delay.