Learn Italian: La descrizione del paesaggio è incredibile. - The description of the landscape is incredible.

It is derived from the verb descrivere (to describe). The suffix -zione is used to turn a verb into a noun that represents the action or result of that verb, very similar to how '-tion' works in English.

Since descrizione is an abstract concept, how do I know its gender?

The suffix -zione is a very reliable rule in Italian: nouns ending in -zione are feminine. This is why it takes the feminine article la. Other abstract suffixes from this lesson, like -ezza and -ità, also create feminine nouns.

Why do we use del instead of just di before paesaggio?

While in English you might occasionally drop the article and say 'description of landscape', Italian requires the definite article here: 'the description of the landscape'. Del is an articulated preposition formed by combining di (of) with il (the masculine singular article for paesaggio).

Descrizione is a feminine noun, so why doesn't the adjective incredibile end in -a?