Police said 13 people were killed and more than 50 wounded in the terror attack, in which a white van sped down a pedestrian zone and swerved from side to side as it ploughed into tourists and residents.
Marriott was about 700m from the attack. He didn't witness it, but he said it was too close for comfort.
Police quickly swarmed into the area and the air above his home was reverberating as helicopters hovered overhead hunting for those responsible.
He said the ordeal had left him shaken to the core.
Marriott said he was now concerned for friends who had gone into the area at the time of the attack but whom he could not reach.
Otago man Eion Willis caught up in terror attack in Barecelona. Photo / Supplied via the Otago Daily Times
Otago man Eion Willis was also in the area during the attack and was barricaded in a shop behind grilled bars for hours as pandemonium broke out around him.
Willis, who was holidaying in Barcelona with his wife and friends, was just 100m from the attack when he was suddenly bustled into a shop.
"We were down an alleyway and then all of a sudden a lot of guys came running and they were chased by other guys. We automatically thought they were pick-pockets and they were being chased but in actual fact there was an actual terror [attack] up in the streets and people were running around in pandemonium trying to find different places to hide."
He said the labyrinth of narrow streets around Las Ramblas immediately went into lockdown.
"All the shops just shut down straight away and anyone in the shops had to stay in the shops and down came the cages.
"You couldn't go anywhere."
He said he was caught on the periphery of the carnage just 10m from the street leading to their motel but had a four hour wait to get back to his accommodation.
Willis said he was not with his wife at the time of the attack who was waiting back at their motel.
