This is a type of Hawaiian lava called pahoehoe. As you can
it's kind of blobby and ropy at the same time. The lava is
enough, even when hot, that it can pile up into these forms.
will form all sort of bizarre patterns that can be quite
interesting. The surface of the lava is quite irregular, so
has to be careful when walking across it.
There is another
of lava, A'a (pronounced ah-ah) which is irregular, sharp, and jagged
that would truly hurt if one were to fall on it. A'a might be
one makes after falling on it, who knows. Lava is very tough
one's boots. After a few days of walking on lava, they looked
like they had aged a few months.