I read in the book of Zechariah 6:1-15 [1] And I turned, and lifted up mine eyes, and looked, and, behold, there came four chariots out from between two mountains; and the mountains were mountains of brass. [2] In the first chariot were red horses; and in the second chariot black horses; [3] And in the third chariot white horses; and in the fourth chariot grisled and bay horses. [4] Then I answered and said unto the angel that talked with me, What are these, my lord? [5] And the angel answered and said unto me, These are the four spirits of the heavens, which go forth from standing before the LORD of all the earth. [6] The black horses which are therein go forth into the north country; and the white go forth after them; and the grisled go forth toward the south country. [7] And the bay went forth, and sought to go that they might walk to and fro through the earth: and he said, Get you hence, walk to and fro through the earth. So they walked to and fro through the earth. [8] Then cried he upon me, and spake unto me, saying, Behold, these that go toward the north country have quieted my spirit in the north country. [9] And the word of the LORD came unto me, saying, [10] Take of them of the captivity, even of Heldai, of Tobijah, and of Jedaiah, which are come from Babylon, and come thou the same day, and go into the house of Josiah the son of Zephaniah; [11] Then take silver and gold, and make crowns, and set them upon the head of Joshua the son of Josedech, the high priest; [12] And speak unto him, saying, Thus speaketh the LORD of hosts, saying, Behold the man whose name is The BRANCH; and he shall grow up out of his place, and he shall build the temple of the LORD: [13] Even he shall build the temple of the LORD; and he shall bear the glory, and shall sit and rule upon his throne; and he shall be a priest upon his throne: and the counsel of peace shall be between them both. [14] And the crowns shall be to Helem, and to Tobijah, and to Jedaiah, and to Hen the son of Zephaniah, for a memorial in the temple of the LORD. [15] And they that are far off shall come and build in the temple of the LORD, and ye shall know that the LORD of hosts hath sent me unto you. And this shall come to pass, if ye will diligently obey the voice of the LORD your God.
See All..., and I have some questions. What are the two mountains of brass? What would be the north country and south country?

I believe the two mountains of brass indicate a time of judgment and the exact location refers to the valley between Mt. Zion and the Mt. of Olives. This valley is called the Valley of Jehoshaphat in Joel 3:2I will also gather all nations, and will bring them down into the valley of Jehoshaphat, and will plead with them there for my people and for my heritage Israel, whom they have scattered among the nations, and parted my land.
See All..., 12. This is the valley of judgment as indicated in Joel 3:14Multitudes, multitudes in the valley of decision: for the day of the LORD is near in the valley of decision.
See All... - "Multitudes, multitudes in the valley of decision: for the day of the LORD is near in the valley of decision." The multitude of Jewish graves on the eastern slope of the Mount of Olives express their desire to be close to the front of the line on judgment day, thinking this to be the time of greater leniency.

The identity of the "north country" (v.6) is difficult to determine exactly. Technically, if it is an individual country, it could be Syria, Iraq, or Russia. It might even be Turkey. However, it probably refers to a northern alliance during the tribulation. Daniel 11 speaks of the "king of the north" 7 times (v.6, 7, 8, 11, 13, 15, 40). It might be an alliance between countries like Syria, Iraq, Turkey, and Russia.

The "south country" always tends to point to Egypt. However, there may be other countries in alliance here as well.

Overall, I still am not settled as to the import of the passage. The brass usually refers to the time of judgment. The valley points to the Valley of Jehoshaphat and the judgment of the nations at the end of the tribulation. However, the exact purpose of the chariots still alludes me. Are they gathering the Gentiles? Or the Jews? Or, are they stirring things up for the battle of Armageddon so that the time of judgment will draw nigh? The bay horses going to and fro (v.7) connect this last night vision with the first one in Zechariah 1 where the horses among the myrtle trees are "they whom the LORD hath sent to walk to and fro through the earth." (1:10). They find the earth at rest (1:11). The time for God to restore Israel has come(1:12-17). The seems to be the meaning in Zechariah 6 as well.  Anyway, the entire passage is fascinating.