Things appear to be very serious between Kim Kardashian and Lewis Hamilton because TMZ has learned the two were on vacation together in Arizona over the weekend.

TMZ has obtained video of Kim and Lewis Saturday evening near Lake Powell, taking in a breathtaking desert sunset, where we're told they were seen snapping a cozy selfie together.

The pair was seen off the beaten path at the secluded spot of the major vacation destination on the Colorado River in Utah and Arizona. The quiet, upscale boating destination is where wealthy travelers typically go for private trips.

The pair were seen in our video heading back to their waiting black SUV parked nearby.

And here's where it gets interesting ... their Lake Powell location puts them within striking distance of Amangiri, the ultra-exclusive five-star resort in Utah near the Arizona border, where Kim and Lewis were staying. The property is a favorite among A-listers, including the Kardashians.

As we reported ... the couple confirmed their relationship with their first public appearance at Super Bowl LX together, where they got super close in the stands.