I always find it interesting that Spain didn't expand its empire during the 19th century.
Much weaker Portugal was much more aggressive than Spain in the scramble for Africa, they sent out expeditions and staked claims to wherever they could. They Portuguese claimed the mouth to the Congo River and were the ones who called for the Berlin Conference, so they check other powers expansion. They even claimed what is now Zambia, Zimbabwe and Malawi and got the French and Germans agreed to this, but in the British didn't. They managed to make the Kingdom of Dahomey a protectorate in 1884, but traded this with the French for their recognising Portugal's pink map. In the end, they still managed to build an impressive empire of over 2 million square kilometres.
At the beginning of the 19th century in Angola, Portuguese control only extended perhaps 400 km inland and was confined to an area between the mouth of the Congo and Benguela to the south (around 250,000 sq km of territory). In Mozambique, Portuguese control was really only confined to small areas around the forts of Ibo, Moçambique, Quelimane, Sofala and Inhambane and up the the Zambezi River to Tete. Hold over Lourenço Marques (Maputo) wasn't even really re-established until the 1870s.
In Portuguese Guinea, only a few forts were in Bissau, Bolama, Cacheu and Ziguinchor (the latter traded with France in 1888 again for them recognising the "Pink Map"). Only in Portuguese Timor did the Portuguese recede when in 1854 the governor of Portuguese Timor sold Eastern Flores, Adonara, Pantar, Loblen, and Solor to the Dutch (without Lisbon's authorization).
As for the Netherlands, their rule in the East Indies was really only confirmed to Java, the Moluccas and bits of Sumatra and Borneo in 1815. They expanded their East Indies Empire to include all of modern Indonesia. However, the Dutch did sell their holdings in the Gold Coast (modern Ghana) and India to the British.
Finally, Belgium and Italy which were no stronger than Spain at the time of the Berlin Conference managed to acquire colonies in Africa as well.
Meanwhile Spain fought a war with Morocco in 1859-1860 and only took Sidi Ifni, even though they had occupied larger territory and won the war. At the Berlin conference they were able to get a strip of desert (Rio de Oro). Even in the Gulf of Guinea they only took tiny Rio Muni in 1900. They had a treay with Portugal granting them the territory between the Niger and Ogogué River, and never did anything with this, They could have easily staked a claim to this area in the 1870s or 1880s.