Halakha Ulangan 12:4: Mishneh Torah, The Chosen Temple, Mishneh Torah, Foundations, Kitzur Shulchan Arukh & Mishneh Torah, Negative Mitzvot

It is forbidden to make steps up to the altar as it says "thou shalt not go up on steps to My altar" rather we build a sort of mound at the southern end of the altar which gets shorter and shorter until it reaches the ground and this is called a 'ramp.' One who ascends the altar on stairs is flogged, as is one who removes a stone from the altar, or from the entire Temple building or from the [area of courtyard] between the Temple and the altar as a destructive measure as it says "thou shalt break up their altars etc." and it says "thou shalt not do so to the LORD thy God."

Whosoever willfully destroys an inscription of any of the Holy and Pure Names by which the Holy One, blessed is He! is called, ¹Menahot, 30. Makkot, 22. Sifre, Deut. 22. C.is guilty of a sin punishable under the laws of the Torah with flogging. For, behold, it is said of idolatry: "And ye shall destroy their name from that place, but ye shall not do so unto the Lord your God" (Deut. 12.3–4).

He who wilfully destroys even one stone of the altar, or of the Temple, or of any other part of the Court, is lashed; for it is said with respect to idolatry: "For their altars must ye demolish," and it is written: "Ye shall not do so unto the Lord your God" (Deut. 12.4)⁸Sifre, Deut. 12. C.; Likewise, if one willfully sets fire to trees intended for sacred use is lashed, for it is said: "And their sacred trees ye shall burn in fire," and it is also written: "Ye shall not do so unto the Lord your God" (Ibid).⁹Makkot, 22. C.