Edit the passage by replacing the adjective with a suitable synonym.
The students discovered the ancient ruin in the mysterious cave.
The students discovered the age-old ruin in the enigmatic cave.
Complete the following task based on the instruction and optional input provided.### Instruction:
Edit the passage by replacing the adjective with a suitable synonym.

### Input:
The students discovered the ancient ruin in the mysterious cave.

### Output:
The students discovered the age-old ruin in the enigmatic cave.