2025  is a very special year
because
2025 = (1 + 2 + 3 + ... + 9)²
and also because
2025 = (1³ + 2³ + 3³ + ... + 9³)

If each slice of the tower (consisting of cubes of diminishing size) is laid on a flat surface (sometimes after cutting slice in half) and nicely rearranged - as is done in above animation - then it visually proofs that
(1³ + 2³ + 3³ + ... + n³) =
(1 + 2 + 3 + ... + n)²