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Double consonants in Spanish

Recently, in a lesson, I came across a question about double consonants in Spanish.

Apart from the well-known ll and rr, what other double consonants can be found in Spanish?

Doble ll (the same sound as a -j- in English) in words such as:
Lluvia, hallar, gallo, batalla, llevar, pollo, … and many more.

Doble rr (pronounced as a rolling strong -r-), we have words like:
Perro, zorro, arrasar, arroz, barro, churro, … and many more.

Also, apart from these two cases we can  find words with:

Double cc (pronounced as -k th-) in words like:
Dirección, perfección, acceso, sección, accidente,

Double nn (pronounced as two -n-):
Perenne, innovar, innato, connotación, …