Giza's Beast - Writing and Revising

I posted an ottava rima for Poetry Friday from a collection of poems I've been working on about Ancient Egypt. These are nonfiction based and meant to be accompanied by a footnote or information section. I'm also working on a glossary. As I draft and revise poems multiple times, I'm very conscious of word choice and poetic form. I thought it might be interesting to share some of my thoughts on this one with you.

First, here's another copy of the poem.

Giza's Beast
Twice buried, twice unearthed from shifting sand,
four thousand years or more it's held this ground.
Colossus carved in limestone ever grand,
recumbent lion with a body crowned
by battered visage that surveys the land.
A monolith that guards the tombs renowned,
three pyramids from massive blocks of stone,
he keeps his secrets silent and alone.

Right now I'm working on the words that need definition. (Keep in mind that these poems are for kids.) I'm beginning with the Oxford English Dictionary, then will revise (simplify?) the definitions with the audience in mind. The first section contains words that must be defined. The second, words that might need to be defined.

Section 1
Colossus - Anything vast or gigantic, or which overawes by its greatness
I was bit worried about the use of this word, because the first definition is "A statue or image of the human form of very large dimensions." The sphinx is, after all, only part human. However, I love the rhythm the word imparts and the way it sounds when read aloud.

Recumbent - Of persons or animals: Lying down, reclining, reposing
I like this word for the same reason I like colossus. It sounds great and so much more sophisticated than lying down. I love words and want kids to appreciate that there are many, many ways to communicate a single idea.

Visage - The face, the front part of the head, of a person
I love this word for face. If you've seen images of the Sphinx, "battered visage" makes a lot of sense. The nose is broken, the eyes pierced with holes, the beard broken from the chin. In fact, it is this missing beard that is the reason the Sphinx was mistaken for having the head of woman.

Monolith - A single block of stone, esp. a large one shaped into a pillar or monument.
I thought it was important to select a word that described how the Sphinx was formed. I also like the way this one sounds. It works well in iambic pentameter.

Section 2
Unearth - To dig out of the earth, to exhume; to disclose by the removal of earth
While this makes sense, I can't see using the word earth in the definition. Perhaps ground or soil would be better choices.

Grand - (1) Eminent; great in reputation, position, scale of operations; (2) Great or important above all others of the kind; (3) With reference to physical magnitude, applied to objects that are magnificent in size and adornment; (4) Characterized by great solemnity, splendour, or display; (5) Of persons, their belongings or surroundings: Fine, splendid, gorgeously arrayed; (6) Used as a general term to express strong admiration: ‘Magnificent’, ‘splendid’.
When I wrote this line, I was going for magnificent. However, I worry I may have too many words that refer to the large size. Is this redundant? When you learn that some of the original paint can still be seen on the head of the Sphinx, I certainly picture it (or try to) in all its past glory.

Crowned - To occupy the head or summit of (a thing)

Battered - Bruised and shattered by repeated blows; worn and defaced by rough or hard usage, the chances of time, etc.

Renowned - Celebrated, famous

If read closely, this poem provides a lot of information about the Sphinx. Are there too many difficult words? That answer rests with the age of the intended readers. For what age do you think this poem is appropriate?

The facts in the poem will need to be reiterated (I think) in the footnote or endnote. Beyond that, I'm still thinking about how much information to include. A few simple sentences or a paragraph. What do you think?