In the book of Acts, a certain temple seems to be being referred to in chapter 2 verse 46:
Every day they continued to meet together in the temple courts.
Which temple is this?
The temple in Jerusalem was destroyed in AD 70.
Acts 2 records how Holy Spirit was poured down on the Day of Pentecost (v 1-4). And then Peter addressed the crowd who were amazed and confused what was going on. Most of them were Jews who came to Jerusalem for the Pentecost festival (v 5). Following Peter's sermon, 3000 were baptized that day (v 41). From verse 42, the writer recorded the activities of the first believers. They devoted to the apostles’ teaching (v 42), they shared everything (v 44) and they met together in the temple courts everyday (v 46).
Acts 2 is no doubt before the destruction of the Temple in Jerusalem. Hence, it refers to the Temple in Jerusalem and none other.
What were they doing in the Temple courts? Meeting together and preaching about Jesus Christ as we see in the immediate next chapter, Acts 3, where Peter and John healed a lame man who was begging at the temple gate.
Acts 3:11 (NIV) While the man held on to Peter and John, all the people were astonished and came running to them in the place called Solomon’s Colonnade.
The believers used to meet together in Solomon’s Colonnade, which was on the eastern side of the temple.
Acts 5:12 (NIV) The apostles performed many signs and wonders among the people. And all the believers used to meet together in Solomon’s Colonnade
You can see the picture of how the temple at that time looked like here in Wikipedia.
In Acts 1:8, Jesus tells the disciples that they will be witnesses for him 1) in Jerusalem, and 2) in all Judea and Samaria, and 3) to the ends of the earth.
But you will receive power when the Holy Spirit has come upon you, and you will be my witnesses in Jerusalem and in all Judea and Samaria, and to the end of the earth.” Acts 1:8 ESV
Acts 2-7 has the disciples 1) in Jerusalem, so the temple in Jerusalem is what they are referring to. After the persecution begins with the stoning of Stephen in Acts 7, the disciples are scattered across 2 Judea and Samaria.
And Saul approved of his execution. And there arose on that day a great persecution against the church in Jerusalem, and they were all scattered throughout the regions of Judea and Samaria, except the apostles. Acts 8:1 ESV
It is this one modelled here:
As you can see, Jerusalem has one big old honking Temple. When someone is DC says, "the Washington Monument" for example, you know they are talking about the big one in the center of town, and not some random little statue there. This would be in contrast to many Asisan cities where there are lots of Temples.
The book of Acts clearly calls out that the disciples were in Jerusalem, and Acts 3:11 points out they were running through Solomon's Collonade, ensuring that in fact yes, it was "the" Temple in Jerusalem.