This is the 120th most frequent Czech word.
světa
The Czech word "světa" means "of the world" (genitive singular of "svět").
In this sentence, 'světa' is again in the genitive singular, showing possession or association with 'krásy' (wonders).
Krásy světa jsou inspirující.
The wonders of the world are inspiring.
'Světa' here is used in the genitive singular form as part of the object of 'záchranu' (rescue), indicating the scope of the action.
Je příliš unavený na záchranu světa.
He is too tired to save the world.
Here, 'světa' is the genitive singular of 'svět' (world), used here to indicate the extent of the action.