Which preposition to use with tumuli

in Occurrences 2%

There are also a great number of small tumuli in the upper part of the park, all of which appear to have been opened.

of Occurrences 2%

We could see the small Red Cross parties in the field climbing over the horribly grotesque tumuli of bodies, trying to disentangle the wounded from the dead and administer first aid to them.

among Occurrences 1%

The site on which this modern house now stands was Roman, before that Early Britain, with burial mounds, before that again, Druidthe Druid stones still lie in that copse below the field, the Tumuli among the ilexes behind the drive.

beneath Occurrences 1%

The land flowed with blood, and along by the railway the ground is dotted with tumuli beneath which are buried the victims of their patriotism.

Which preposition to use with  tumuli