check on Blokkers https://maproulette.org/browse/challenges/41299
check on Blokkers https://maproulette.org/browse/challenges/41299
check on Blokkers https://maproulette.org/browse/challenges/41299
check on Blokkers https://maproulette.org/browse/challenges/41299
check on Blokkers https://maproulette.org/browse/challenges/41299
check on Blokkers https://maproulette.org/browse/challenges/41299
check on Blokkers https://maproulette.org/browse/challenges/41299
check on Blokkers https://maproulette.org/browse/challenges/41299