The Ark of the Covenant is a biblical vessel, described in (1 Kings 8:9) as solely containing the Tablets of Stone on which the Ten Commandments were inscribed. According to Hebrews 9:4 and some traditional interpretations of Exodus 16:33-34 and Numbers 17:25-26 (or Numbers 17:10-11 in some translations), the Ark also contained Aaron's rod and a jar of manna.
Detailed instructions are given by God himself for the plan of the Ark: it is to be 2½ cubits in length, 1½ in breadth, and 1½ in height (as 21⁄2×11⁄2×11⁄2 royal cubits or 1.31×0.79×0.79 m). Then it is to be plated entirely with gold, and a crown or molding of gold is to be put around it. Four rings of gold are to be put into its four feet—two on each side—and through these rings staves of shittim-wood overlaid with gold for carrying the Ark are to be inserted; and these are not to be removed. A golden cover, adorned with golden cherubim, is to be placed above the Ark.
My Ark is made by real gold plated parts (thanks so much to Auri and Ansgar, they'll recognize themselves!).
It may find its place one day in a big white Solomon's Temple... but this is another story!