Ark of the Covenant
Ark of the Covenant contains the almond-budded staff of Aaron, the 10 commandments, and the manna. It was like a treasure box that only the Levites were allowed to carry. Looking inside is forbidden and will cause death. It was lost to the Philistines on 2819 FC (1149 BC) and was recovered after 20 yrs (2839 FC 1129 BC).
From Wikipedia
The Ark of the Covenant (Hebrew: אָרוֹן הַבְּרִית, Modern: Arōn Ha'brēt, Tiberian: ʾĀrôn Habbərîṯ; Koinē Greek: κιβωτος της διαθηκης), also known as the Ark of the Testimony, and in a few verses across various translations as the Ark of God, is a gold-covered wooden chest with lid cover described in the Book of Exodus as containing the two stone tablets of the Ten Commandments. According to various texts within the Hebrew Bible, it also contained Aaron's rod and a pot of manna. Hebrews 9:4 describes: "The ark of the covenant [was] covered on all sides with gold, in which was a golden jar holding the manna, and Aaron's rod which budded, and the tablets of the covenant."
The biblical account relates that, approximately one year after the Israelites' exodus from Egypt, the Ark was created according to the pattern given to Moses by God when the Israelites were encamped at the foot of biblical Mount Sinai. Thereafter, the gold-plated acacia chest was carried by its staves while en route by the Levites approximately 2,000 cubits (approximately 800 meters or 2,600 feet) in advance of the people when on the march or before the Israelite army, the host of fighting men. When carried, the Ark was always hidden under a large veil made of skins and blue cloth, always carefully concealed, even from the eyes of the priests and the Levites who carried it. God was said to have spoken with Moses "from between the two cherubim" on the Ark's cover. When at rest the tabernacle was set up and the holy Ark was placed in it under the veil of the covering, the staves of it crossing the middle side bars to hold it up off the ground.