Beach construction (last of cabanas and shed) left emptyParseword Answer

How to solve this Parseword clue

The clue resolves to sandcastle through the numbered wordplay changes below. Each step keeps the original phrase visible so the solution can be checked line by line.

1. Step 1selectionIndicator: last of

   last of cabanas becomes s

2. Step 2substitution

   left becomes l

3. Step 3substitution

   empty becomes e

4. Step 4substitution

   shed becomes cast

5. Step 5charade

   s and cast l e becomes sandcastle