They (Nanda Maharaja and all the cowherd men) had come to some place other than Vrndavana. They could not actually guess what had happened, and therefore they were struck with wonder - after seeing Putana's gigantic body

Expressions researched:
"they had come to some place other than Vṛndāvana. They could not actually guess what had happened, and therefore they were struck with wonder"

Srimad-Bhagavatam

SB Canto 10.1 to 10.13

Nanda Mahārāja's wonder may be understood in various ways. First of all, the cowherd men had never before seen such a gigantic body in Vṛndāvana, and therefore they were struck with wonder. Then they began to consider where such a body had come from, whether it had dropped from the sky, or whether, by some mistake or by the power of some mystic yoginī, they had come to some place other than Vṛndāvana. They could not actually guess what had happened, and therefore they were struck with wonder.

SB 10.6.31, Translation and Purport

Meanwhile, all the cowherd men, headed by Nanda Mahārāja, returned from Mathurā, and when they saw on the way the gigantic body of Pūtanā lying dead, they were struck with great wonder.

Nanda Mahārāja's wonder may be understood in various ways. First of all, the cowherd men had never before seen such a gigantic body in Vṛndāvana, and therefore they were struck with wonder. Then they began to consider where such a body had come from, whether it had dropped from the sky, or whether, by some mistake or by the power of some mystic yoginī, they had come to some place other than Vṛndāvana. They could not actually guess what had happened, and therefore they were struck with wonder.