The destruction of the temple seems to be blended here with the end of time, and things are not super clear.
This chapter is almost entirely a sustained speech by Jesus, which is prompted by some observations about the impermanence of the temple. Some of it seems quite specifically about the temple in Jerusalem, and this makes the most sense of some of the details. Other sections sound a lot like the apocalypse, which is how the Adventist church usually reads it. We discuss wars, famines, and rumours-of-wars - but can't help comparing the weighty topics of this chapter against the way Jesus points out a generous widow in the preceding verses.