Right in the centre of mainland Spain
No, Cameroon is a country in its own right, situated on the west coast of Africa
Spain
I assume you mean the left of Spain. Upon its formation, yes, Portugal has always been Portugal. However, before there was a Portugal, there were other Kingdoms and Empires in its place. For example, the Roman Empire. Spain used to also occupy all of the Iberian Peninsula, in which the two countries are situated. Before the modern-day Portugal, there was the Kingdom of Portugal.
The liver is situated in the right higher abdominal area, directly below and behind the lowest ribs.
Relative to the rest of Spain, Madrid is in the center.
Ever heard of a map?
"Situated at the center" implies that the subject is located in close proximity to the central point, but not necessarily directly in the middle. On the other hand, "situated in the center" specifically denotes being positioned at the exact midpoint of a given area or object. The distinction lies in the precision of the placement, with "at the center" allowing for a bit more leeway in interpretation compared to "in the center."
Right here
Spain is the border of Portugal. If you are looking at a map, it'll be on your right, and the maps left.
Agadir, Morocco is in the southern part of country of Morocco. Morocco is located in the Northwestern region of Africa right below Spain and right above the Western Sahara Desert.
Barcelona is right by the Mediterranean sea. In fact it's the largest city on the Med.