stumble upon (?.)
- alight upon
- arrive at
- arrive upon
- blunder upon
- bump into
- chance upon
- come across
- come at
- come on
- come up against
- come upon
- discover serendipitously
- encounter
- fall in with
- fall upon
- get at
- happen upon
- hit upon
- light upon
- meet up with
- meet with
- pitch upon
- reach
- run across
- run into
- run up against
- strike upon
- stumble on
- tumble on