HEAVEN Revelation 11:19

Then God's temple in heaven was opened, and within his temple was seen the ark of his covenant. And there came flashes of lightning, rumblings, peals of thunder, an earthquake and a great hailstorm.

Then God's temple in heaven was opened
Revelation 15:5 After this I looked and in heaven the temple, that is, the tabernacle of the Testimony, was opened.
Revelation 15:8 And the temple was filled with smoke from the glory of God and from his power, and no one could enter the temple until the seven plagues of the seven angels were completed.

and within his temple was seen the ark of his covenant
Exodus 25:22 (Read verses 10-22 for the complete description) There, above the cover between the two cherubim that are over the ark of the Testimony, I will meet with you and give you all my commands for the Israelites.
2 Chronicles 5:7 The priests then brought the ark of the Lord's covenant to its place in the inner sanctuary of the temple, the Most Holy Place, and put it beneath the wings of the cherubim.
Hebrews 9:3-4 Behind the second curtain was a room called the Most Holy Place, which had the golden altar of incense and the gold-covered ark of the covenant. This ark contained the gold jar of manna, Aaron's staff that had budded, and the stone tablets of the covenant.

And there came flashes of lightning, rumblings, peals of thunder
Revelation 4:5 From the throne came flashes of lightning, rumblings and peals of thunder. Before the throne, seven lamps were blazing. These are the seven spirits of God.

an earthquake and a great hailstorm
Revelation 16:21 From the sky huge hailstones of about a hundred pounds each fell upon men. And they cursed God on account of the plague of hail, because the plague was so terrible.

NOTES:
Ark of his covenant - Deuteronomy 10:1-2; 2 Kings 25:8-10

(Parentheses are mine)

Scriptures taken from the Holy Bible, New International Version® NIV®, Copyright© 1973, 1978, 1984 by International Bible Society. Used by permission. All rights reserved worldwide.