A Lenten outdoor meditation walk could include encouragement to pick up rocks and sticks and use them to create artworks, such as those of Patti Rokus (Rocks Tell Stories).
Patti writes:
Nature and her gifts, such as rocks, can be a catalyst for us to find wholeness again. Rocks can be a way to deepen our connection to God and to ourselves.
I'm offering a simple way to play, relax, and reconnect to ourselves and to God. Finding, organizing and creating with common rocks and pebbles is a calming activity that opens space in our hearts for God to enter and fill us with love.
Here is her video about Lent that focuses on service and Jesus washing the disciples' fee (ignore the date given for start of Lent, this is a video from a few years ago):
And a screenshot from that video: