diff --git a/README.md b/README.md
index 951ae91..6805bf8 100644
--- a/README.md
+++ b/README.md
@@ -225,6 +225,7 @@ for transferring data with URLs.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://findsubdomains.com/"><b>Find subdomains online</b></a> - find subdomains for security assessment penetration test.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://dnsdumpster.com/"><b>DNSdumpster</b></a> - dns recon & research, find & lookup dns records.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://dnstable.com/"><b>DNS Table online</b></a> - search for DNS records by domain, IP, CIDR, ISP.<br>
+&nbsp;&nbsp;:small_orange_diamond: <a href="https://securitytrails.com/dns-trails"><b>DNS Trails</b></a> - repository of historical DNS data.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="http://ptrarchive.com/"><b>PTRarchive.com</b></a> - this site is responsible for the safekeeping of historical reverse DNS records.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="http://xip.io/"><b>xip.ip</b></a> - wildcard DNS for everyone.<br>
 </p>