Gibeon was the GREAT high place

[TonyChanYT]

1 Kings 3:

3 Solomon loved the LORD, walking in the statutes of David his father, only he sacrificed and made offerings at the high places.

Generally speaking, worshipping at high places was a sin. There seemed to be an exception:

4 And the king went to Gibeon to sacrifice there, for that was the great high place.

Let's check the parallel account in 2 Chronicles 1:

2 Solomon spoke to all Israel, to the commanders of thousands and of hundreds, to the judges, and to all the leaders in all Israel, the heads of fathers’ houses. 3And Solomon, and all the assembly with him, went to the high place that was at Gibeon, for the tent of meeting of God, which Moses the servant of the LORD had made in the wilderness, was there.

There were some important artifacts located in this high place.

4(But David had brought up the ark of God from Kiriath-jearim to the place that David had prepared for it, for he had pitched a tent for it in Jerusalem.) 5Moreover, the bronze altar that Bezalel the son of Uri, son of Hur, had made, was there before the tabernacle of the LORD. And Solomon and the assembly sought it out. 6And Solomon went up there to the bronze altar before the LORD, which was at the tent of meeting, and offered a thousand burnt offerings on it.

Apparently, God honored the offerings:

7In that night God appeared to Solomon, and said to him, “Ask what I shall give you.”

Before the Jerusalem temple was completed, Gibeon was the great high place where worship was accepted.