Here is a list of the oldest 100 websites in the world,(just The 100 Oldest Currently Registered .COM Domains). The oldest website is symbolics.com(1985/3/15),which is 23 years old, in fact, younger than me 😉
1. symbolics.com 1985/3/15
2. bbn.com 1985/4/24
3. think.com 1985/5/24
4. mcc.com 1985/7/11
5. dec.com 1985/9/30
6. northrop.com 1985/11/7
7. xerox.com 1986/1/9
8. sri.com 1986/1/17
9. hp.com 1986/3/3
10. bellcore.com 1986/3/5
11. ibm.com 1986/3/19
12. sun.com 1986/3/19
13. intel.com 1986/3/25
14. ti.com 1986/3/25
15. att.com 1986/4/25
16. gmr.com 1986/5/8
17. tek.com 1986/5/8
18. fmc.com 1986/7/10
19. ub.com 1986/7/10
20. bell-atl.com 1986/8/5
21. ge.com 1986/8/5
22. grebyn.com 1986/8/5
23. isc.com 1986/8/5
24. nsc.com 1986/8/5
25. stargate.com 1986/8/5
26. boeing.com 1986/9/2
27. itcorp.com 1986/9/18
28. siemens.com 1986/9/29
29. pyramid.com 1986/10/18
30. alphacdc.com 1986/10/27
31. bdm.com 1986/10/27
32. fluke.com 1986/10/27
33. inmet.com 1986/10/27
34. kesmai.com 1986/10/27
35. mentor.com 1986/10/27
36. nec.com 1986/10/27
37. ray.com 1986/10/27
38. rosemount.com 1986/10/27
39. vortex.com 1986/10/27
40. alcoa.com 1986/11/5
41. gte.com 1986/11/5
42. adobe.com 1986/11/17
43. amd.com 1986/11/17
44. das.com 1986/11/17
45. data-io.com 1986/11/17
46. octopus.com 1986/11/17
47. portal.com 1986/11/17
48. teltone.com 1986/11/17
49. 3com.com 1986/12/11
50. amdahl.com 1986/12/11
51. ccur.com 1986/12/11
52. ci.com 1986/12/11
53. convergent.com 1986/12/11
54. dg.com 1986/12/11
55. peregrine.com 1986/12/11
56. quad.com 1986/12/11
57. sq.com 1986/12/11
58. tandy.com 1986/12/11
59. tti.com 1986/12/11
60. unisys.com 1986/12/11
61. cgi.com 1987/1/19
62. cts.com 1987/1/19
63. spdcc.com 1987/1/19
64. apple.com 1987/2/19
65. nma.com 1987/3/4
66. prime.com 1987/3/4
67. philips.com 1987/4/4
68. datacube.com 1987/4/23
69. kai.com 1987/4/23
70. tic.com 1987/4/23
71. vine.com 1987/4/23
72. ncr.com 1987/4/30
73. cisco.com 1987/5/14
74. rdl.com 1987/5/14
75. slb.com 1987/5/20
76. parcplace.com 1987/5/27
77. utc.com 1987/5/27
78. ide.com 1987/6/26
79. trw.com 1987/7/9
80. unipress.com 1987/7/13
81. dupont.com 1987/7/27
82. lockheed.com 1987/7/27
83. rosetta.com 1987/7/28
84. toad.com 1987/8/18
85. quick.com 1987/8/31
86. allied.com 1987/9/3
87. dsc.com 1987/9/3
88. sco.com 1987/9/3
89. gene.com 1987/9/22
90. kccs.com 1987/9/22
91. spectra.com 1987/9/22
92. wlk.com 1987/9/22
93. mentat.com 1987/9/30
94. wyse.com 1987/10/14
95. cfg.com 1987/11/2
96. marble.com 1987/11/9
97. cayman.com 1987/11/16
98. entity.com 1987/11/16
99. ksr.com 1987/11/24
100. nynexst.com 1987/11/30
and at last, this is mine, dobeweb.com